High impulse explosives containing tungsten



United States Patent 3,528,864 HIGH IMPULSE EXPLOSIVES CONTAINING TUNGSTEN Clarence E. Weinland, China Lake, Calif., assignor to the United States of America as represented by the Secretary of the Navy No Drawing. Filed Sept. 21, 1965, Ser. No. 489,471 Int. Cl. C06b 15/02 US. Cl. 149-92 3 Claims ABSTRACT OF THE DISCLOSURE An explosive composition which has improved impulsive effect for each unit volume for use Where a minimum volume of explosive is needed for a given level of effectiveness. It consists essentially of a high explosive loaded with tungsten. The tungsten improves the effectiveness of the explosive due to the physical effect of its massiveness in increasing the transfer of momentum and impulse from the explosive to the surrounding bodies.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

This invention relates to an improved explosive composition; more particularly, to high impulse explosives.

In general, high explosives are compositions and mixtures of ingredients capable of instantaneously releasing large amounts of energy and doing work of various kinds on the objects and bodies surrounding them. In some cases the useful work that is done is limited only by the energy content of the explosive composition, while in other cases the transfer of energy from explosive composition to surrounding bodies is controlled to a large degree by the momentum or impulse released by the detonating explosive. The present invention is for an improved explosive composition which has greater impulsive effect for each unit of its volume.

It is therefore an object of the present invention to provide a composition for use in military ordnance where a minimum volume of explosive is needed for a given level of impulsive effectiveness.

Another object is to provide an explosive composition for military fragmenting weapons which is capable of projecting fragments at a high velocity.

A further objective is to provide a composition which is capable of propelling heavier metal objects in contact with it at high velocity, whether such metal objects are heavier by virtue of their having greater thickness or by virtue by their being composed of metals of greater inherent density.

Still another object is to provide an explosive which when placed in contact with a layer of metal and detonated by a detonation wave proceeding in the direction parallel to the contact face between explosive and metal, will project the metal in a direction which is at a greater angle to the normal to the pre-detonation metal surface.

Yet another object is to provide an explosive of lower detonation velocity and higher impulsive effectiveness for use in combination with higher detonation velocity explosives in wave-shaping applications and applications Where a detonation wave must be guided in particular directions in order to accomplish useful purposes.

A further object is to provide an explosive capable of moving metal bodies in contact with it or doing other useful work on them but without shattering them or fragmenting them in the process.

Another object is to provide an improved high impulse explosive for use in a shaped charge application.

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Other objects, features and many of the attendant advantages of this invention will become readily appreciated as the same become better understood by reference to the following detailed description when considered in connection with the following examples.

The present invention is for an explosive consisting essentially of one or more known detonating organic compositions mixed with a metal having a density greater than the composition. Tungsten was the metal used. The detonating organic compositions were selected from a group of high explosives consisting of trinitrotoluene (TNT), cyclotrimethylene-trinitramine (RDX), cyclotetramethylene tetranitramine (HMX), diaminotrinitrobenzene (DATB), composition C-3, and composition C4. Composition C-3 consists essentially of 77 percent RDX ann 23 percent explosive plasticizer, the plasticizer being composed of mononitrotoluene, dinitroluene, trinitrotoluene, tetryl, and nitrocellulose. Composition C-4 consists essentially of 91 percent RDX, 2.1 percent polyisobutylene, 1.6 percent motor oil and 5.3 percent di(2- ethylhexyl)sebacate. The tungsten is intended to increase the density of the explosive composition. The amount added is adjusted to attain a desired level judged by its product of density times detonation velocity. Tungsten does not necessarily enter chemically into the detonation reaction, nor does it produce gaseous detonation products. The effectiveness of this additive is believed to be due to the physical effect of its massiveness in increasing the transfer of momentum and impulse from the explosive to surrounding bodies. The material added must have a greater density than 1.75 grams per milliliter. The tungsten powder used in the practice of this invention has a true density of 19.3 grams per milliliter; its apparent or bulk density may range from 1.75 to 6.0 grams per milliliter, powders of 2.0 and 4.6 grams per milliliter density having been used in the various examples.

The following examples are given for better understanding only and no unnecessary limitations are to be understood therefrom.

EXAMPLE I Ingredients: Percent 'by weight Composition C-3 50 Tungsten (6 particle size) 50 Composition C-3 is a plastic demolition explosive which has been standardized by the United States. It contains 77i2 percent by weight of cyclotrimethylenetrinitramine (RDX) and 23 :2 percent by weight explosive plasticizer. The plasticizer contains mononitrotoluene, a liquid mixture of dinitrotoluenes, trinitrotoluene (TNT), tetryl and nitrocellulose. It is a yellowish putty-like solid that has a density of 1.6. Composition C-3 and tungsten were hand mixed, the tungsten being first wet with motor oil which acts as a processing aid. The mixture was contained in a 6-inch long cylinder of mild steel, 2 inches in inside diameter and having a 0.25-inch wall. The firing data for this explosive is as follows: measured detonation velocity, 6,049 meters per second; corrected fragment velocity, 1,268 meters per second. The density of the composition is 4.17 grams per cc., and the charge-to-metal ratio of the test as fired was 0.564. The velocity of fragments to be expected from a similar steel cylinder of the same dimensions filled with percent C-3 may be calculated from the well-known Gurney formula and is 1,223 meters per second. From these data it is possible to calculate that a warhead filled with the explosive composition mentioned in this example will give fragments of exactly the same velocity as a warhead filled with 100 percent of Composition C-3 if the warhead has a ratio of case volume to case weight of 0.645 cubic centimeters per gram, and that in warheads of lower ratio of case volume to case weight, the 50 percent tungsten composition mentioned in this example will give greater fragment velocity in all cases, the spread between the velocities becoming greater as the volume/weight ratio becomes less.

' EXAMPLE 11 Ingredients: Percent by weight Composition C-3 75 Tungsten (1.1,u particle size) 25 The Composition C-3 and tungsten were hand mixed, the tungsten being first wet with light mineral oil as a processing aid. The mixture was contained in micarta tubes of approximately 1 /2 inches inside diameter and l-foot length for the determination of detonation velocity. The average detonation velocity for five shots was found to be 6,550 meters per second. The detonation velocity for 100 percent of C-3 is well-known to be 7,625 meters per second.

This same composition was used in the construction of inverted shaped charges known as the punch charge. When contained in the same explosive container as would hold 3 pounds of 100 percent C-3, the composition described here was found to be capable of punching the same diameter hole through the same thickness target plate as the C-3, but in firing three separate tests, in every case, the cylindrical slug of metal punched out of the target plate was found to be whole and unshattered, whereas in the case of the firings with C-3 the plug was invariably found to have been fragmented and spalled.

EXAMPLE III Ingredient: Percent by weight Trinitrotoluene (TNT) 25 Tungsten 75 These ingredients were mixed by adding the tungsten powder to molten TNT, the mixture being stirred and poured into a mild steel cylinder. The density of this explosive is 5.624 grams per cc. as compared to 1.5 6:01 for TNT alone.

Powdered uranium can be used to increase the massiveness of high explosives. The purpose of the dense metals is to form a composition in which the physical property of density provides a quality which enables the explosive to transfer extraordinary momentum and impulse to sur- 1 rounding objects with which it is in contact when detonated. This is different from the ordinary objectives of obtaining greater brisance, or detonation pressure, or detonation power or specific detonation energy. The com: positions disclosed herein produce greater fragment velocity, shaped charge effects as related to greater masses of jet and slug, or compression shock in surrounding material, from a relatively small volume, and to produce these elfects with less shattering of the metal being moved, as compared to other known high explosives.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the intended claims invention may be practiced otherwise than as specifically described.

What is claimed is:

1. A high impulse explosive consisting essentially of from 25 to percent by weight tungsten and from 50 to percent by weight of a composition consisting essentially of 77 percent cyclotrimethylenetrinitramine and 23 percent plasticizer consisting of a mixture of mononitrotoluene, dinitrotoluene, trinitrotoluene, tetryl and nitrocellulose.

2. A high impulse explosive consisting essentially of from 50 to 75 percent by weight tungsten, and

from 25 to 50 percent by :weight trinitrotoluene.

3. A high impulse explosive consisting essentially of about equal parts of a high explosive selected from the group consisting of a composition comprising cyclotrimethylene-trinitramine, mononitrotoluene, dinitrotoluene, trinitrotoluene, tetryl, and nitrocellulose; diaminotrinitrobenzene; trinitrotoluene; cyclotrimethylene-trinitramine;

cyclotetramethylenetetranitramine; and mixtures thereof;

and tungsten.

References Cited UNITED STATES PATENTS 1,054,777 3 1913 Imperiali 149l05 XR 2,548,880 4/1951 Fassnacht et a1 14992 3,160,535 12/1964 Wells 149l05 XR BENJAMIN R. PADGE'IT, Primary Examiner S. I. LECHERT, JR., Assistant Examiner US. Cl. X.R. 14988, 96, 99, 100, 105, 106, 107 

